Lloyd alan laflin



July 5 A1927.

L. A. LAFLIN MOVEMENT `CONVERTING DEVICE FOR METERS Filed Nov. 11, 1926 Patented July 5, 19.27.r

UNITED STATES PATsNroFFIcE.

LLOYD ALAN LAFLIN, OF LAKE FOREST, ILLINOIS, ASSIGNOR TO LGIN NATIONAL ITaTCl-T COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MOVEMENT-CONVERTING DEVICE FOR METERS.

Application'filedV November 11, 1926. Serial No. 147,792.' y,

This invention relates toimprovements in movement converting devices'and indicators whereby angular movements are converted into rectilinear movements.

Dial meters, of the type employing an oscillating shaft and'indicating finger are old and Well known in many arts. In'employing such meters,`it isnecess'ary to provide forl their reception a panel space at least equal 1U to the areaof theface of the instrument, al-

though a large portion of this area is not effectively employed. Ina great many em ployments of such devices, a sufiicient area is not available for the reception of the necessary instruments of various typesras required for thel operation of the particular machine-upon which they arev located. An instance of this is the instrument boa-rdof an airplane, in which it is necessary to employ a greatmanyinstruments of-various shaft into a rectilinear ,movement of an in. dlcatlng device along a `rectilinear. scale Whichis substantially vertical onlthe ordinary airplane. In this Way, the space on the instrument board is conserved,since y1t is only necessaryto provide a space slightly y larger than that occupied by an easily read 40 scale. Y

The number of VWorking parts is reduced to a'minimum'fso that thevr strainnpon the actuating shaftl of the tachometer is reduced and the accuracy of `the Vfinal kindication is'.

unimpaired vby' largetorques, which is of great technicaladvantage;` as" it is necessary in devices of this type to havea moving sysv tem of very lightelements, .so that-the torques employed` arevery small, Weight is conserved, and unnecessary strains upon the driving and returning mechanism `are avoided. The light Weights of `.the several parts and their arrangement to substantially' balance `each other permits the device to operatev accurately even When the airship is flying upside down.

In particular, according to the present device an angular displacement may be transmitted and-converted'into a rectilinear displacement: and since with revolution counters of the` type for eXample of Patent 1,447,426 of March 6,' 1923, the angular movement of the oscillatiirsg;` shaft varies by equal angles for equal Aincrements or decrements of speed, this movement is transmitted as equal displacements ina rectilinear direction of the indicating fingeror index. In this Way, the distance ofztravel of the index is exactly proportionate to the angular movement which Would be made by an indieating finger onj the shaft itself.

YThis apparatus has been'illustrated on the accompanying drawings by `Way of'eXample as applied to a tachometer or revolution counter for-anairship.

Figure l is a side elevation of the 'casing and dial, with the cover removed.

F ig. 2 vis a face view of the dia1.-

F ig. 8 is a section on line 8 3 of Fig. 2.

'It-Willbe understood that this invention is to be applied topa-meter or measuring-de-v vice of any knoivntype: and that only as an illustrative form has it been shownV as applied to a tachometer of the'type now manufactured under `the, Prouty etal. YPatentNo. 1,447,426. i Y

The actuating shaft of represented on the present drawing as the tacliometer properis fixed in an appropriate manner to the casing 12 of the` instrument, which has a planeY front `1,2a parallel to the -shaft A1.0 and with its cover 12F serves as a protection yto `prevent the entry of' oil vand dirt. The mechanism 'ofthe tachometer is driven in Well known manner by a flexible shaft lvvhich enters thecasing through the this tachometer is Voscillating shaft 10.;v The casing 11 of this customary bushing-14, and presents its inner Y crankshaft of the engine. Themovements of the tachometer mechanism cause angular movements of the oscillatingl shaft 1t) by equal increments for equal changes of speed of the engine. lf', for example, the engine is turning,` at 150() revolutions. the shaft 10 will have departed by fifteen equal angular divisions from its position of rest, and upon an increase of speed to 1700 revolutions per minute, the shaft will move through Atwo :further divisions, ctc.

Securely fastened to the front 12nu ot' the casing' 12 is a plate 15 having a protective glass 1G therein to guard a scale 1"? which is preferably of metal and is divided and lettered at 1S to furnish a reference scale for the readingl olf the instrument. A slot 19 preferably extends in this first plate 17 tor at least the distance from the zero indication to above the maximum speed inditation.

The pulleys 20 and 21 are respectively journaled on fixed pins mounted on the casing; These pulleys are mounted opposite and in line with the slot 19 on the face 15. Mounted lixed ly on the oscillatingl shaft 10 is a drum which has a flexible member 2lsuch as a chain or cable fastened at a point olf its periphery, so that as the shat't 10 is rotated in a clockwise direction in 1, the member Q-il is wound up thereon: and when the oscillating shaft 10 rotates in the opposite direction, this member is permitted to unwind. rl`he member Q1 passes over the pulleys Q0 and 21, and on its course between them passes close to and parallel with the slot" 19. After leaving the pulley 21, the member Q11 passes to a further or take-up drum 2G and is fastened to a point QT on the periphery thereof. This talteup drum is carried on a journal pin Q8 fastened to the casing 12, and has attached to one l'ace a smaller or spring driving drum 29, which in like manner has connected at a point of its periphery a spring` connection cable 31 which extends to and is coupled with one end ot the helical take-up spring 32, which at its other end is vfastened to an eye 33 attached to the casing 12.

Mounted ixedly on the flexible member 2li between the pulleys 2O and :21 is an index finger which projects through the slot 19 and has a pointer 3ft visible from the outside eil the face 15 through the glass 16. It :is preiierred that this pointer 3d be provided with a radium compound for visibility at night.

In the :form shown in Fig. 3, the face member 15 and the glass 16 are shown as enclosing the scale 18 which is mounted upon a metal member 17 which is raised above the gen-eral level of the member 12a whereby to provide a clearance for the pointer 34:1.

In ope lation, as the speed of the engine increases, the flexible shaft 13 causes a corresponding increase in the motion of the taehoinetcr, whereby the actuating shaft 1() is caused to move in a clockwise direction to correspond thereto. During.;- this movement, the drum draws upon the llexible member Q- l and winds it up upon its own periphery. .lfhe member Q-l carries the pointer or index 3l upward for a distance which corresponds by equal increments to the equal increments ot angular `movements of the oscillatingl shaft 10 under the impulse of the tachometer 11. The flexible member 2l duringr this unwinds from the talie-up drum :2G and by the coupling of' the latter with the spring drum 29, causes a tensioning;- of the take-up springl 32.

lllhen the speed of the engine decreases, the actuatingr sha'lt, l() movesin a counter clockwise direction, and releases the tension on the cable 2l for a certain amount of potential slack. This slack is innnediately tal-:en up by the tal eup spring 3Q in an inverse manner to that described above, whereby the pointer or index 3l. moves to its new location.

It is obvious that the drumsQS, 2G and 29, as well as the pulleys Q0 and 21, may be made very light, and that their pivoting entails no greatfriction. The flexible member 24; has very little work to perform in moving' the pointer 3l since this is `guided in the slot 19 with butY slight friction. The take-up spring 32 may therefore be very light and weak and in its turn reacts very little in torque upon the actuating shaft' 10, whereby the indications are very accurate.

1t is obvious that the invention may be applied in any wise apart from the illustra tive example shown and .more particularly many modifications may be made in the form of execution without departing from the .scope of the appended claims.

What is claimed as new is:

1. movement converting device for4 indicators having` a shaft oscillated by a meteringl mechanism by equal angular dietances for equal increments `and decrcments o' the quantity being measured, a rec-` tilinear graduate-e scale and an index therefor, an operatingl drum fixed on said shaft, guide pulleys at the ends of the said scale, a flexible member passingl over said pulleys and connected to the said index and connected at one end to said drum, means tof main tain the other end ot' said member under a normal retin'ninel tension, whereby said index is moved by equal linear distances along said scale for such equal angular movements of said` shaft.

A movement converting' device for indicators having a .shaft oscillated by a metering mechanism by equal angular distances for equal increments and deereinents` of the quantity being measured, a rectilinear graduated scale and an index therefor,

Ilfi

an operating drum fixed on said shaft, guide pulleys at the .ends of said scale, a iiexible member passing over said pulleys and connected to the said index and connected at one end to the said drum, a take-up .drum

having a pivot xed relative to said shaft and connected to the other end of said member, and a spring to exert a torque upon said take-up drum to take up said member during the unWinding movement of .saidv mension, a casing having a front Wall With .a straight slot therein, said Wall being in a plane parallel to the axis of said shaft, a rectilinear scale on said front wall adja- .cent said slot, an index movable along said slot to cooperateJ with said scale, and means actuated by said shaft to move said index by equal linear distances for equal angular y movements of said shaft, said actuated means including a drum secured to said Y shaft, a exible member secured by one end to Vsaid drum, and a talre-up Idevice connected to the other end ofthe flexible member to maintain the same under tension, the total Width of said scale and'slot being substantially that of the thickness of said meter.

In testimony whereof, I afx my signature.

LLOYD ALAN LAFLIN. 

